This proposal represents our efforts to employ a molecular approach to understand the clinical features and etiology of papillomatosis, including any possible progression of benign tumors to malignancy. The fundamental objective of this proposal is to determine whether viruses associated with benign warty tumors (papillomas) in humans can be identified in malignant tissue, affecting similar anatomical sites and suspected to have arisen from such papillomas. We have, over the past several years, accumulated a large number of patients with unusual wart syndromes for these studies. Several of these patients exhibit lifelong wart disease with super-imposed skin cancer (e.g., epidermodysplasia verruciformis). We have also collected tissues from patients with large warts affecting the skin, ano-genital region, and oral cavity that have progressed to frank squamous cell carcinomas. Since most papillomas (with the exception of cutaneous warts) do not produce sufficient amounts of HPV for analysis we have employed a purification scheme to identify and purify covalently closed circular HPV DNA from these papillomas. This procedure has already enabled us to purify HPV DNA from condylomata acuminata (genital warts) in sufficient quantities to both characterize the DNA and initiate hybridization studies of a variety of carcinoma tissues. We will radiolabel purified HPV DNAs in vitro to high specific activities and then utilize this DNA as a probe to determine (1) if HPV-related sequences can be identified in malignant tissue that is suspected to have arisen from papillomas; (2) the genetic relatedness of new isolates of HPV to known HPVs; (3) if the HPV genome, or a fraction thereof, is integrated in papilloma and related malignant tissue, and the location of the integration site(s); and (4) the extent to which the HPV genome, or fraction thereof, is expressed in papillomas and related malignant tumors. The procedures to be employed in these studies include DNA-DNA reassociation, restriction endonuclease analysis, heteroduplex analysis, Southern transfer technique, and DNA-RNA hybridization.